Prilenia Therapeutics and Ferrer to Present New Pridopidine Data and PREVAiLS Trial Updates at NEALS 2026
Prilenia Therapeutics B.V. and Ferrer have announced plans to present new clinical data and updates on the ongoing PREVAiLS study at the Northeast Amyotrophic Lateral Sclerosis (NEALS) Consortium 2026 Annual Meeting in Florida. The presentations will highlight additional analyses of pridopidine, an investigational therapy being evaluated for amyotrophic lateral sclerosis (ALS), as well as progress in the development of the Phase 3 PREVAiLS clinical trial.
The latest findings include a post hoc analysis of participants with definite or probable ALS who were within 18 months of the onset of their first disease symptoms. The analysis used data from the Phase 2 HEALEY ALS Platform Trial and its open-label extension, comparing outcomes among participants who received pridopidine with external control data from the Pooled Resource Open-Access ALS Clinical Trials (PRO-ACT) database.
According to the companies, the analysis identified favorable findings across several measures, including the ALS Functional Rating Scale–Revised (ALSFRS-R), respiratory assessments and median survival time through Week 48. Comparisons with external controls were conducted using propensity-score weighting methods to account for differences between the groups.
The findings build on earlier post hoc analyses from the 24-week placebo-controlled phase of the HEALEY Platform Trial. These results have contributed to the rationale and design of PREVAiLS, an ongoing registrational Phase 3 randomized, controlled study evaluating pridopidine in a similar patient population.
Recruitment for PREVAiLS is progressing, with approximately 60% of the planned participants enrolled. Prilenia and Ferrer expect to complete recruitment of approximately 500 participants in the first quarter of 2027, with topline results anticipated in the first quarter of 2028.
New Analysis Examines Early-Stage ALS
The new post hoc analysis included 36 participants with definite or probable ALS according to the El Escorial diagnostic criteria who were within 18 months of their first disease symptoms. The analysis drew on data from the HEALEY ALS Platform Trial, registered under ClinicalTrials.gov identifier NCT04615923, and its open-label extension phase.
ALS is a progressive neurodegenerative disease that affects nerve cells responsible for controlling voluntary muscles. As the disease advances, patients can experience increasing muscle weakness, difficulties with movement and speech, swallowing problems and declining respiratory function. Disease progression varies among individuals, but the condition can substantially affect independence, daily activities and survival.
The early stages of ALS are an important area of clinical investigation because changes in physical function and respiratory capacity may emerge as the disease progresses. Researchers are evaluating potential treatments that could preserve function, slow deterioration or improve other clinically meaningful outcomes.
By focusing on participants who were within 18 months of symptom onset, the analysis examined pridopidine in a subgroup characterized by a relatively early stage of disease. The results may help inform the development program’s understanding of treatment outcomes in this population, although the small subgroup size and post hoc nature of the analysis are important considerations when interpreting the findings.
Post hoc analyses examine data after a study has been completed or after the primary analysis has been planned. They can help researchers explore patterns in specific patient populations and generate hypotheses for further testing. However, such analyses are generally considered exploratory and do not carry the same evidentiary strength as a prospectively designed, adequately powered randomized comparison.
Outcomes Include Functional and Respiratory Measures
According to Prilenia and Ferrer, pridopidine was associated with favorable results across three key areas through Week 48 when compared with external PRO-ACT controls: functional outcomes measured using ALSFRS-R, respiratory measures and median survival time.
The ALSFRS-R is a commonly used clinical assessment that evaluates the impact of ALS on physical functioning. It measures activities across several domains, including speech, swallowing, handwriting, walking, self-care and respiratory function. Changes in the scale can help researchers assess how the disease affects patients’ ability to perform everyday activities.
Respiratory assessments are also important in ALS clinical trials because the disease can progressively weaken the muscles involved in breathing. Monitoring respiratory function can provide information about disease progression and help investigators evaluate whether an investigational treatment may be associated with differences in respiratory decline.
Survival is another clinically important outcome in ALS research. Analyses of median survival time can provide information about the duration of survival within a studied population, although the interpretation depends on the study design, follow-up period, participant characteristics and statistical methods used.
The reported Week 48 findings suggest that pridopidine warrants continued evaluation in the targeted patient population. However, the announcement does not establish that the investigational drug definitively slows ALS progression or extends survival. The reported associations require confirmation through appropriately designed clinical studies.
External Control Comparisons Use Propensity-Score Weighting
The analysis compared participants receiving pridopidine with external controls drawn from the PRO-ACT database, a resource that brings together data from ALS clinical trials to support research into disease progression and treatment outcomes.
External controls can be useful when investigators want to explore outcomes against a broader reference population, particularly when a subgroup from a clinical study is small. However, comparisons between separate datasets may be affected by differences in eligibility criteria, baseline characteristics, assessment schedules, supportive care and other factors.
To address some of these differences, the researchers used propensity-score weighting methods. These statistical approaches estimate the likelihood that participants belong to a particular treatment group based on observed characteristics. Weighting can then help improve the comparability of groups across measured variables.
Although propensity-score methods can reduce the influence of observed differences, they cannot eliminate all potential sources of bias. Differences in unmeasured characteristics or data collection methods may still affect the results.
For this reason, findings from external control comparisons are generally interpreted as supportive evidence rather than a substitute for a randomized, controlled clinical trial. The ongoing PREVAiLS study is expected to provide additional evidence through a prospective randomized design.
Findings Build on the HEALEY ALS Platform Trial
The new analysis follows earlier post hoc subgroup findings from the 24-week placebo-controlled phase of the HEALEY ALS Platform Trial.
Platform trials allow researchers to evaluate multiple investigational therapies within a shared clinical infrastructure. This model can support more efficient study operations and provide a structured framework for assessing potential treatments for diseases with significant unmet medical needs.
The HEALEY trial has contributed data to the development of pridopidine by enabling investigators to examine outcomes in the studied population. The subsequent open-label extension has provided an additional setting for evaluating participants over a longer period, although results from an open-label phase must be interpreted with care because treatment assignment and expectations may influence assessments.
According to the companies, the earlier findings helped inform the rationale for PREVAiLS, which is designed to evaluate pridopidine in a similar population through a registrational Phase 3 randomized, controlled study.
The move into Phase 3 represents an important stage in clinical development. Larger, prospectively designed trials are generally required to determine whether an investigational therapy provides a clinically meaningful benefit and has an acceptable safety profile in the intended population.
PREVAiLS Phase 3 Trial Reaches Approximately 60% Enrollment
The PREVAiLS study is the next major step in Prilenia and Ferrer’s clinical development program for pridopidine in ALS. The registrational trial is planned to enroll approximately 500 participants and is evaluating the investigational treatment in a patient population similar to the subgroup examined in the latest analysis.
The companies reported that enrollment has reached approximately 60% of the target population.
Recruitment is expected to be completed in the first quarter of 2027, while topline results are anticipated in the first quarter of 2028. These timelines remain subject to the progress of enrollment, trial execution and the availability of study data.
The randomized, controlled design is intended to provide a more rigorous assessment of pridopidine than can be obtained through exploratory subgroup analyses and external control comparisons. The findings will be important in determining whether the treatment demonstrates sufficient evidence of benefit to support further regulatory discussions.
The study’s results may also help clarify how pridopidine performs in patients at an earlier stage of ALS, a population that is the focus of the recent post hoc analysis.
NEALS 2026 to Highlight Continued Clinical Development
The planned presentations at the NEALS Consortium 2026 Annual Meeting will provide an opportunity to share additional information about pridopidine and the progress of its clinical development program.
NEALS brings together researchers and clinical professionals working to advance ALS research and improve care for people living with the disease. Scientific meetings provide a forum for investigators to discuss emerging findings, examine research methods and identify questions that require further study.
For Prilenia and Ferrer, the meeting will serve as a platform to present the latest subgroup analysis and provide an update on the PREVAiLS trial’s enrollment progress and development timeline.
The findings are particularly relevant given the continuing need for therapies that can meaningfully affect the course of ALS. Although treatment and supportive care can help address symptoms and complications, disease progression remains a major challenge for patients, families and healthcare professionals.
Next Steps for Pridopidine
Prilenia Therapeutics and Ferrer continue to advance pridopidine through clinical development, with the ongoing PREVAiLS Phase 3 trial representing a key milestone in the program.
The latest post hoc analysis reported favorable associations across functional, respiratory and survival measures through Week 48 in a subgroup of 36 participants with early-stage ALS, compared with propensity-score-weighted external controls from PRO-ACT.
While these findings add to the evidence being examined by the companies, their exploratory nature and the small subgroup size mean that they should not be regarded as definitive proof of efficacy.
The anticipated completion of recruitment in the first quarter of 2027 and topline results in the first quarter of 2028 will be important milestones for the program. Results from the randomized, controlled PREVAiLS study are expected to provide further clarity on the safety and potential clinical benefits of pridopidine in ALS.
For now, the new analysis and trial update underscore the companies’ continued efforts to investigate pridopidine as a potential treatment option for people living with this progressive neurological disease.
About ALS
Amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig’s disease or often referred to as motor neuron disease (MND), is a progressive neurodegenerative disease, which means it is a chronic condition that gets worse over time as damage builds up in parts of the nervous system. It affects the motor neurons in the brain and spinal cord and leads to a gradual loss of muscle function that eventually results in paralysis and deathv.
ALS has a global prevalence of approximately 4.42 per 100,000 peoplevi, and is more frequent in men than in womenvii. The average survival is 2 to 5 yearsviii. The exact cause of ALS is not fully understood, but it is believed to be a combination of genetic and environmental factors.
ALS typically appears in individuals aged 40 to 70 and presents a range of symptoms, including muscle weakness and atrophy, mobility issues such as lack of coordination and balance, muscle spasms, difficulty speaking clearly (dysarthria), trouble swallowing (dysphagia), fatigue, and emotional and cognitive changesix. Symptoms worsen over time and significantly impact the quality of life of patients and their families by affecting their ability to perform daily activities independently. Current treatment options are limited.
About pridopidine
Pridopidine is an investigational highly selective, oral sigma-1 receptor (S1R) agonist. S1R has been shown to play a role in stimulating multiple neuroprotective pathways impaired in neurodegenerative diseases, such as Huntington’s disease (HD) and amyotrophic lateral sclerosis (ALS)x.
In clinical studies to date, pridopidine (taken as an oral capsule twice a day) has shown a generally favorable safety and tolerability profile, with data from more than 1,600 people (mostly from HD studies), some of whom have received active treatment for up to seven yearsxi.
Pridopidine is currently in late-stage clinical development for HD and ALS. It has Orphan Drug Designation in HD and ALS in the US and EU, and FDA Fast Track designation in the US for the treatment of HD. These designations do not imply that pridopidine has been approved, or that safety and efficacy have been established.
About PREVAiLS (Pridopidine Phase 3 Study to Evaluate Efficacy and Safety in ALS)
PREVAiLS is a pivotal, global, 500-participant, randomized, placebo-controlled Phase 3 study designed to further evaluate the efficacy and safety of pridopidine, an investigational medicinal product, in people living with amyotrophic lateral sclerosis (ALS) early in the course of their disease.
The study seeks to enrol participants with definite or probable ALS, according to the El Escorial Criteria, who are within 18 months from the first onset of disease symptoms. Its design is informed by findings from a subgroup analysis of the Phase 2 HEALEY ALS Platform Trial in a similar early, rapidly progressing patient population. The pridopidine regimen of the HEALEY ALS Platform Trial did not meet its primary endpoint in the overall study population.
PREVAiLS comprises a 48-week placebo-controlled stage, with participants randomised to receive pridopidine or placebo on a 3:2 basis, followed by a 48-week open-label extension stage. The primary endpoint is the change from baseline in the Revised Amyotrophic Lateral Sclerosis Functional Rating Scale (ALSFRS-R), adjusted for mortality, at Week 48.
Secondary and exploratory endpoints include survival and measures of speech, respiratory function, bulbar function and quality of life, as well as patient-reported outcomes of communication and plasma biomarkers.
The study is planned across up to 60 leading ALS treatment centers across 13 countries, including in the US, Canada, EU, UK and Israel.
More details on PREVAiLS can be found on ClinicalTrials.Gov (NCT07322003) / EU CT Number: 2025-524002-16-00 and at www.prevailstrial.com.
About Prilenia
Prilenia is a private biopharmaceutical company driven by an unwavering commitment to scientific excellence and accelerating progress for people affected by Huntington’s disease (HD), amyotrophic lateral sclerosis (ALS) and other neurodegenerative disorders. Our mission is simple but urgent: to develop and provide sustainable access to transformative medicines for people affected by devastating neurodegenerative diseases.
The company is incorporated in the Netherlands and backed by leading life sciences investors. Prilenia and Ferrer are partners in the co-development and commercialisation of pridopidine. For more information, please visit www.prilenia.com, and connect with us on LinkedIn, X or Instagram.
About Ferrer
At Ferrer, we use business to fight for social justice. We have long been a company that wants to do things differently; instead of maximizing shareholder returns, we reinvest much of our profit in initiatives that give back to society. Back where it belongs. We go beyond compliance and are guided by the highest standards of sustainability, ethics and integrity. As such, since 2022, we are a B Corp.
Founded in Barcelona in 1959, Ferrer offers transformative solutions for life-threatening diseases in more than one hundred countries. In line with our purpose, we have an increasing focus on pulmonary vascular and interstitial lung diseases and rare neurological disorders in adults and children. Our 1,800-strong team is driven by a clear conviction: our business is not an end in itself, but a way to change lives.